A dark brown bench suspended between two white and grey rectangular pillars. They are capped in the same brown HDPE material. Aluminum uprights go to a curved solar panel roof that looks somewhat similar to a paragliding chute. The bench is inside a clean-looking workshop with two large toolboxes against a plywood half wall.

Public Power, WiFi, And Shelter

In the US, we’re starting to see some pushback against hostile architecture, and in this vein, [benhobby] built a swanky public power and Wi-Fi access point.

This beautiful piece of infrastructure has 400 watts of solar plugged into 1.2 kWh of battery storage, and can dispense those electrons through any of its 120 VAC, USB-C, or USB-A plugs. The uprights are 3″ aluminum tubing attached to a base consisting of cinder blocks and HDPE panels. Power receptacles are housed in 3D printed enclosures with laser cut acrylic fronts. Three outdoor lights illuminate the stop at night, triggered by a photosensor.

The electronics and battery for the system, including the networking hardware, are in a weatherproof box on each side that can be quickly disconnected allowing field swaps of the hardware. Troubleshooting can then take place back at a workshop. One of the units has already been deployed and has been well-received. [benhobby] reports “There’s one in the wild right now, and it gets plenty of visitors but no permanent tenants.”

Want to see some more interesting hacks for public infrastructure? Check out this self-cooling bus stop, this bus bloom filter, or this public transit display.

A series of tubes wound up and down as modules in a metal-framed, free-standing wall. The wall is inside a climate-controlled test chamber with a series of differently-colored tubes running behind the free-standing wall.

Cooling Off The Bus Stop

If you’ve taken the bus in the summer, you know it can get hot while you wait on your ride, even if there is a roof over the stop. Researchers at the University of Seville have devised a way to keep you cooler while you wait.

As temperatures around the world get warmer due to climate change, keeping cool in the summer is increasingly not just a matter of comfort. For the prototype in a climate-controlled chamber, 500L of water were cooled with a chiller and used as a thermal reservoir to reduce temps in the bus stop during the day. Pumps circulate the water through panels when a rider approaches the stop, cooling the space by ~8˚C (~14˚F) over a 20 minute period. Pumps for the system and lighting for the stop will be powered via solar panels and keep the system self-contained.

The amount of cooling offered by the system can be controlled by the flow rate of the water. The researchers plan to use Falling-Film radiant cooling in the outdoor version to replace the chiller to cool the water at night. They also say the system can be used for radiant heating in the winter, so it isn’t just for hot climates.

If you want to know how to survive a wet bulb event or want a better way to determine your bus route, we’ve got you covered there too.

[via Electrek]

Bus Stop Bloom Filter

Imagine you’re sitting on a nice bench, the sun shines warmly, and a bus pulls up. You’re headed to Stendal from Osnabrück, how can you tell if you should get on that bus? [Julian Vanecek] is trying to turn that from an O(n) problem to an O(1) one with a Bloom filter right at the bus stop.

In [Julian’s] sample code, each stop is a 3-bit number that can be encoded into a 192-bit array. Your ticket is just that 3-bit number encoded, so you can look at the graphic on the side of the incoming bus, match it against your ticket, and hop on. Gone are the days of waiting for the little LED screen to cycle through all the stops, waiting for yours to come up. Your ticket should have just a few boxes filled in so it is relatively quick to search against the bus’s graphic.

Of course, there is a potential for a false positive rate. [Julian] points out that this can be tuned to prevent errors and has achieved a < 0.5% false positive rate using the Deutsche Bahn bus system. The code is written in Python and available on GitHub. Perhaps buses could have a large flip-dop display on the side, to adjust to show which stops they’re headed to next. Additionally, it doesn’t encode which stops are next, just which stops the bus will eventually go to.

In the video after the break, [Julian] explains how the system works. Whether it would be ultimately adopted is somewhat beside the point. We love the seeing people re-imagining ideas and trying to apply new techniques to improve the things around them.

Continue reading “Bus Stop Bloom Filter”